Boron hydride salts, in particular the nonmetal salts of decahydrodecarboric acid, have been discovered to have particular utility in the field of high energy fuels. They may be used as constitutents of pyrotechnic compositions, and in rocket propellants. The present invention teaches a new nonmetal salt of decahydrodecaboric acid, which exhibits stable physical properties and exhibits several unusual pyrotechnic properties, in that the material deflagrates at a very rapid rate without the deflagration becoming a detonation.
A particular objective in preparing compounds suitable for certain types of pyrotechnic usage is to achieve a high gas output and low molecular weight combustion products, when the fuel is burned with a suitable oxidizing agent. Combustion products such as hydrogen (H.sub.2) and nitrogen (N.sub.2) gas fulfill this requirement. In preparing salts useful as pyrotechnic fuels from an anion such as decahydrodecaborate (-2) (B.sub.10 H.sub.10.sup.-2), it is therefore advantageous to use a cation containing a high weight fraction of atomic nitrogen and hydrogen. The guanidinium ion, chemical formula C(NH.sub.2).sub.3.sup..sup.+1 has been found to be such a cation. In addition, the corresponding Bronsted base of the ion, free guanidine, is a strong base, which imparts to the cation, and thus the salt, a high degree of chemical stability.